Prevalence of HPV infection among Thai schoolgirls in the north-eastern provinces in 2018: implications for HPV immunization policy.

Objective: The aim of this study was to determine the prevalence of high-risk (HR) and vaccine-type human papillomavirus (HPV) infection among Thai schoolgirls who were not included in the national HPV immunization program. Methods: Cross-sectional surveys were conducted among grade 10 (15-16 years old) and grade 12 (17-18 years old) schoolgirls in two provinces of Thailand. Urine samples were collected using the Colli-PeeⓇ device from November 2018 to February 2019. The samples were initially tested using CobasⓇ 4800. Subsequently, all Cobas-positive samples and 1:1 matched Cobas-negative samples were tested by AnyplexⓇ assay. Prevalences of any HPV, any HR HPV, vaccine-type HPV, and individual HR HPV types were estimated by school grade. Results: Prevalences of any HPV and any HR HPV were 11.6% and 8.6% for grade 10, and 18.5% and 12.4% for grade 12 schoolgirls, respectively. Prevalences of bivalent vaccine-type HPV infection in grades 10 and 12 were 3.4% and 4.5%, respectively. Prevalences of quadrivalent and nonavalent vaccine-type HPV infections were 4.0%/6.6% and 6.4%/10.4% in grades 10 and 12, respectively. HPV16 was the most common type detected, followed by HPV58, 51, and 52. Circulating HR HPV types were similar between the school grades. Conclusion: A substantial burden of HR HPV infections was found among unvaccinated high school girls in Thailand.

A community intervention effectiveness study of single dose or two doses of bivalent HPV vaccine (CERVARIX®) in female school students in Thailand.

Human papillomavirus (HPV) is a common infection principally spread through sexual activity. Most HPV infections are asymptomatic and resolve spontaneously. However, persistent infection may progress to cervical cancer. Highly efficacious HPV vaccines have been available since 2006, yet uptake into national programs has been slow in part due to cost. WHO guidelines call for a two-dose (0,6 month) schedule for girls 9-14 years of age. Post-hoc analyses of randomized trials have found high vaccine effectiveness following a single dose of vaccine. In order to provide additional data on the potential impact of single dose HPV vaccination in a real-world setting, we are conducting an effectiveness study among Thai schoolgirls. This is an observational study of a single dose (SD) or two doses (2D) of the bivalent HPV vaccine CERVARIX® (GlaxoSmithKline plc.) administered in a school-based program to 8-9,000 Grade 8 female students in two provinces of Thailand beginning in 2018; one province is assigned the SD, and the other the standard 2D regimen. The reduction in HPV vaccine-type prevalence will be assessed in each province two and four years after vaccination by comparing HPV prevalence in urine samples obtained through cross-sectional surveys of the immunized grade cohort as they age and compared to a historical "baseline" HPV prevalence of same age students.

Economic evaluation of rotavirus vaccination: an important step of the introduction to the national immunization program in Thailand.

INTRODUCTION: World Health Organization recommends rotavirus vaccine for all national immunization programs (NIPs). To provide country-specific evidence, we conducted economic evaluation of a monovalent rotavirus vaccination using specific data of the pilot phase in Thailand. METHOD: A Markov model was adopted to compare the 2020 birth cohort once receiving rotavirus vaccination versus no vaccination from healthcare and societal perspective over five years. Data on disease burden, vaccine effectiveness, costs, and utilities were taken from a cohort study in two provinces of Thailand.  Sensitivity analyses were performed to test the robustness of the results. RESULTS: Rotavirus vaccination would reduce rotavirus diarrhea and costs of illness by 48% and 71%, respectively, over the first five years of life. At USD 13 per dose, vaccine was cost-effective with the ICERs of USD 4,114 and USD 1,571per QALY gained from healthcare and societal perspective, respectively. Results were sensitive to incidence and vaccine cost.  The budget for vaccine purchasing was estimated at USD13 million per year. CONCLUSION: Incorporating rotavirus vaccination into the NIP substantially reduced health and cost outcomes and was cost-effective for both perspectives. However, the government needs to negotiate vaccine price prior to program implementation to achieve favorable budget impact.

Economic burden of rotavirus diarrhea in Thailand: Report from a pilot study on rotavirus vaccination.

BACKGROUND: Rotavirus diarrhea is the leading cause of morbidity and mortality in young children in both developed and developing countries. Hospitalization costs are a significant burden of both governments and households. The objective of this study was to estimate the economic burden associated with the hospitalization of children with non-rotavirus and rotavirus diarrhea in two provinces in Thailand. METHOD: A prospective incidence-based cost-of-illness study was conducted on children under five years old with acute diarrhea who had been admitted to public hospitals in two provinces during October 2012 and June 2013. Caregivers were interviewed to estimate costs from a societal perspective at 2014 values. Stool samples were examined for rotavirus antigens. Multivariate regression analysis was used to assess the relationship of predictor variables to costs. Annual economic burden of rotavirus hospitalization was estimated by multiplying the number of hospitalized children and the hospitalization cost per episode. The costs were converted to international dollars (I$) using purchasing power parity (PPP) (1 USD = 12.36 baht for the year 2014). RESULTS: Seven hundred and eighty-eight cases of acute diarrhea were included in the analysis. Of the total, one hundred and ninety-seven (25%) were detected as being rotavirus positive. Total societal costs of inpatient care per episode were 822.68 USD (10,165 Baht). The average costs of children with and without rotavirus were 903.39 USD (11,162 Baht) and 795.40 USD (9,827 Baht), respectively. Based on the multiple regression analysis, rotavirus infection, severity, and younger age were significantly associated with the higher costs. CONCLUSION: Diarrhea, rotavirus diarrhea in particular, represents of a substantial economic burden in the society in Thailand. The accurate estimates that societal costs of the rotavirus diarrhea hospitalizations provide valuable input for considering a preventive program.

Evaluating the first introduction of rotavirus vaccine in Thailand: Moving from evidence to policy.

BACKGROUND: We assessed the effectiveness and possible impact of introducing rotavirus vaccine into the routine immunization program. METHODS: Two provinces were selected for an observational study, one where vaccine was introduced and another where vaccine was not available. In these areas, two sub-studies were linked. The prospective cohort study enrolled children 2month old and followed them to the age of 18months to detect all diarrhea episodes. The hospital surveillance study enrolled all children up to age 5 hospitalized with diarrhea whose fecal samples were tested for rotavirus. Rates of rotavirus hospitalizations in older children who had not been vaccinated in both settings provided data to determine whether immunization had an indirect herd effect. The key endpoints for the study were both vaccine effectiveness (VE) based upon hospitalized rotavirus diarrhea and herd protection. FINDINGS: From the cohort study, the overall VE for hospitalized rotavirus diarrhea was 88% (95%CI 76-94). Data from hospital surveillance indicated that for 2 consecutive years, the seasonal peak of rotavirus admissions was no longer present in the vaccinated area. Herd protection was observed among older children born before the rotavirus vaccine program was introduced, who experienced a 40-69% reduction in admission for rotavirus. CONCLUSIONS: Rotavirus vaccine was highly effective in preventing diarrheal hospitalizations and in conferring herd protection among older children who had not been vaccinated.

Prevalence of chronic hepatitis B virus infection in Thailand: a systematic review and meta-analysis.

OBJECTIVE: To estimate the number of people living in Thailand with chronic hepatitis B (CHB), a major cause of liver cirrhosis and cancer, in view of the implementation of programs to prevent CHB complications. METHODS: Using PubMed/Medline and ScienceDirect, all studies reporting hepatitis B surface antigen (HBsAg) seroprevalence estimates conducted in Thailand and published between 1975 and 2015 were reviewed systematically. Pooled prevalence estimates and their 95% confidence intervals (CIs) were calculated, and potential sources of heterogeneity investigated. RESULTS: A high heterogeneity was observed between prevalence estimates. There was a significant decrease in the 150 estimates of HBsAg prevalence with more recent decades of birth (p<0.001), even before the implementation of the national universal immunization program in 1992. When restricted to the general population, the pooled prevalence estimate was 5.1% (95% CI 4.3-6.0%), which would translate to an estimated number of individuals with CHB living in Thailand in 2015 as high as three million. CONCLUSIONS: The high burden of CHB in Asian countries is a major challenge for the incorporation of national programs to prevent CHB complications within health care systems.

Economic analysis for evidence-based policy-making on a national immunization program: a case of rotavirus vaccine in Thailand.

Severe diarrhea caused by rotavirus is a health problem worldwide, including Thailand. The World Health Organization has recommended incorporating rotavirus vaccination into national immunization programs. This policy has been implemented in several countries, but not in Thailand where the mortality rate is not high. This leads to the question of whether it would be cost-effective to implement such a policy. The Thai National Vaccine Committee, through the Immunization Practice Subcommittee, has conducted an economic analysis. Their study aimed to estimate the costs of rotavirus diarrhea and of a rotavirus vaccination program, and the cost-effectiveness of such a program including budget impact analysis. The study was designed as an economic evaluation, employing modeling technique in both provider and societal perspectives. A birth cohort of Thai children in 2009 was used in the analysis, with a 5-year time horizon. Costs were composed of cost of the illness and the vaccination program. Outcomes were measured in the form of lives saved and DALYs averted. Both costs and outcomes were discounted at 3%. The study found the discounted number of deaths to be 7.02 and 20.52 for vaccinated and unvaccinated cohorts, respectively (13.5 deaths averted). Discounted DALYs were 263.33 and 826.57 for vaccinated and unvaccinated cohorts, respectively (563.24 DALYs averted). Costs of rotavirus diarrhea in a societal perspective were US$6.6 million and US$21.0 million for vaccinated and unvaccinated cohorts, respectively. At base case, the costs per additional death averted were US$5.1 million and US$5.7 for 2-dose and 3-dose vaccines, respectively, in a societal perspective. Costs per additional DALYs averted were US$128,063 and US$142,144, respectively. In a societal perspective, with a cost-effectiveness threshold at 1 GDP per capita per DALYs averted, vaccine prices per dose were US$4.98 and US$3.32 for 2-dose and 3-dose vaccines, respectively; in a provider perspective, they were US$2.90 and US$1.93. One-way and probabilistic sensitivity analyses were included. The budget required for vaccine purchase was calculated for all scenarios.